JP2012060838A - Power supply device and vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a sudden change in a voltage acting on an apparatus when a connection state between a first secondary battery and a second secondary battery as viewed from the apparatus is switched.SOLUTION: A power supply device includes: a battery 40 including a negative electrode side terminal connected to a negative electrode bus 35; a battery 42 including a positive electrode side terminal connected to a first positive electrode bus 36; relays Rp1 and Rp2 interposed between the positive electrode side terminals of the batteries 40 and 42 and between the negative electrode side terminals of the batteries 40 and 42, respectively; a relay Rs interposed between the positive electrode side terminal of the battery 40 and the negative electrode side terminal of the battery 42; a step-up converter 34 connected to the negative electrode bus 35, the first positive electrode bus 36 and a second positive electrode bus 37 to which the positive electrode side terminal of the battery 40 is connected; and a relay Rc provided in the second positive electrode bus 37. A connection state of the batteries 40 and 42 viewed from an inverter 32 is switched while the relay Rc is maintained in on state and a voltage between the negative electrode bus 35 and the first positive electrode bus 36 is adjusted by means of the step-up converter 34.

Description

  The present invention relates to a power supply device and a vehicle on which the power supply device is mounted, and more particularly to a power supply device that exchanges power with a device that is operated by electric power, and a vehicle on which the power supply device is mounted.

  Conventionally, as this type of power supply device, a first power storage unit having a negative electrode connected to one terminal of an inverter for driving a motor, a second power storage unit having a positive electrode connected to the other terminal of the inverter, A first switch interposed between the positive electrode of the first power storage unit and the positive electrode of the second power storage unit, a second switch interposed between the negative electrode of the first power storage unit and the negative electrode of the second power storage unit, and the positive electrode of the first power storage unit And a third switch interposed in the negative electrode of the second power storage unit has been proposed (see, for example, Patent Document 1). In this device, the first power storage unit and the second power storage unit can be connected in parallel by turning on the first switch and the second switch and turning off the third switch. By turning on and turning off the first switch and the second switch, the first power storage unit and the second power storage unit can be connected in series.

JP 2010-57288 A

  In the above-described power supply device, the voltage acting on the inverter may change suddenly when the switch is turned on and off when switching between the parallel connection state and the series connection state. If the voltage acting on the inverter changes suddenly, a large inrush current may flow between the first power storage unit or the second power storage unit and the inverter, or the controllability of the inverter may be reduced. It is preferable to suppress the sudden change as much as possible.

  The power supply device and the vehicle according to the present invention are mainly capable of suppressing a sudden change in the voltage acting on the device when the connection state between the first secondary battery and the second secondary battery as viewed from the device is switched. Objective.

  The power supply apparatus and vehicle of the present invention employ the following means in order to achieve the main object described above.

The power supply device of the present invention is
A power supply device for exchanging power with a device that operates by electric power,
A first secondary battery in which a negative electrode side terminal is connected to a negative electrode bus to which a negative electrode side terminal of the device is connected;
A second secondary battery having a positive terminal connected to a first positive bus connected to the positive terminal of the device;
A first relay for connecting and releasing the connection between the positive terminal of the first secondary battery and the positive terminal of the second secondary battery;
A second relay that connects and disconnects the negative electrode side terminal of the first secondary battery and the negative electrode side terminal of the second secondary battery;
A third relay for connecting and releasing the connection between the positive terminal of the first secondary battery and the negative terminal of the second secondary battery;
A device connected to the second positive electrode bus connected to the positive terminal of the first secondary battery, the first positive electrode bus and the negative electrode bus, and being a voltage between the first positive electrode bus and the negative electrode bus A step-up converter capable of adjusting a voltage to be equal to or higher than a pre-boosting voltage that is a voltage between the second positive electrode bus and the negative electrode bus;
A fourth relay provided on the second positive electrode bus for connecting and releasing the positive electrode side terminal of the first secondary battery and the boost converter;
It is a summary to provide.

  In the power supply device of the present invention, the first secondary battery in which the negative electrode side terminal is connected to the negative electrode bus to which the negative electrode side terminal of the device operated by electric power is connected, and the first positive electrode in which the positive electrode side terminal of the device is connected. Connection and disconnection of the second secondary battery having the positive terminal connected to the bus, the positive terminal of the first secondary battery, and the positive terminal (first positive bus) of the second secondary battery are performed. A first relay, a second relay that connects and disconnects the negative electrode side terminal (negative electrode bus) of the first secondary battery and the negative electrode side terminal of the second secondary battery, and the positive electrode side of the first secondary battery A third relay for connecting and disconnecting the terminal and the negative electrode side terminal of the second secondary battery, a second positive electrode bus, a first positive electrode bus and a negative electrode bus connected to the positive electrode side terminal of the first secondary battery Is connected to the first positive electrode bus and the negative electrode bus, and the device voltage is negative with respect to the second positive electrode bus. A boost converter that can be adjusted to a voltage before boosting that is a voltage between the bus and the booster; and a fourth converter that is provided on the second positive bus and performs connection and disconnection between the positive side terminal of the first secondary battery and the boost converter. And a relay. With such a hardware configuration, when switching the connection state between the first secondary battery and the second secondary battery as seen from the device, the device voltage is adjusted by the boost converter with the fourth relay turned on. It is possible to switch. Therefore, it is possible to suppress a sudden change in the device voltage when switching the connection state between the first secondary battery and the second secondary battery as viewed from the device. Here, as a connection state of the first secondary battery and the second secondary battery as viewed from the device, the first relay is on and the second relay, the third relay, and the fourth relay are off. The state in which only the first secondary battery among the first secondary battery and the second secondary battery is connected to the device, the second relay is on, the first relay, the third relay, and the fourth relay Is in a state in which only the second secondary battery is connected to the device among the first secondary battery and the second secondary battery, and the third relay is on and the first relay and the second relay And the fourth relay are turned off, so that the first secondary battery and the second secondary battery are connected in series when viewed from the device, the first relay and the second relay are turned on, and the third relay is turned on. When the relay and the fourth relay are off, the first secondary battery and the second secondary battery A condition to be connected in parallel when viewed from the device can be considered at least a part of.

  In such a power supply device of the present invention, the first secondary battery and the second second relay are activated when the first relay and the second relay are on and the third relay and the fourth relay are off. The second battery is connected in parallel when viewed from the device, and the third relay is on and the first relay, the second relay, and the fourth relay are off. When switching between a serial connection state in which the first secondary battery and the second secondary battery are connected in series when viewed from the device, switching is performed while the device voltage is adjusted while the fourth relay is turned on. It is also possible to include switching control means for controlling the step-up converter, the first relay, the second relay, the third relay, and the fourth relay.

  In the power supply device according to the aspect of the present invention in which the device voltage is adjusted by the boost converter while the fourth relay is turned on when switching between the parallel connection state and the series connection state, the switching control means includes the parallel connection When switching from the state to the series connection state, the fourth relay is controlled so that the fourth relay is turned on, and the step-up converter of the first positive bus is connected to the fourth relay with the fourth relay turned on. The boost converter is controlled so that no current flows in a predetermined range on the second secondary battery side from the connection point of the first relay, and the first relay and the second relay in a state where no current flows in the predetermined range The first relay and the second relay are controlled such that the device voltage is turned off, and the device voltage is set to the first secondary battery in a state where the first relay and the second relay are turned off. The boost converter is controlled to be equal to or higher than the sum of the voltage and the voltage of the second secondary battery, and the device voltage is equal to or higher than the sum of the voltage of the first secondary battery and the voltage of the second secondary battery. In this state, the third relay is controlled so that the third relay is turned on, and the second secondary battery is charged and discharged while the third relay is turned on, and the second positive electrode The step-up converter is controlled so that no current flows through the bus, the second secondary battery is charged and discharged, and the fourth relay is turned off with no current flowing through the second positive bus. The fourth relay may be a means for controlling the fourth relay. By so doing, it is possible to suppress a sudden change in the device voltage when the third relay is turned on.

  Further, in the power supply device according to the aspect of the present invention in which the device voltage is adjusted by the boost converter while the fourth relay is turned on when switching between the parallel connection state and the series connection state, the switching control means includes the series control unit. When switching from the connected state to the parallel connection state, the fourth relay is controlled so that the fourth relay is turned on, and a current flows through the second positive electrode bus while the fourth relay is turned on. The step-up converter is controlled so that the second secondary battery is no longer charged / discharged, and the current flows through the second positive electrode bus and the second secondary battery is no longer charged / discharged. The third relay is controlled so that the relay is turned off, and the first relay and the second relay are turned on while the device voltage is adjusted with the third relay turned off. The step-up converter, the first relay, and the second relay are controlled so that the fourth relay is turned off while the first relay and the second relay are turned on. It can also be a means for controlling the fourth relay. If it carries out like this, when the 1st relay and the 2nd relay are turned ON, it can suppress that an apparatus voltage changes suddenly. In the power supply device according to the aspect of the present invention, the switching control unit may switch the first secondary voltage after the third relay is turned off when switching from the series connection state to the parallel connection state. The boost converter is controlled to be equal to the higher one of the voltage of the battery and the voltage of the second secondary battery, and the device voltage is the voltage of the first secondary battery and the voltage of the second secondary battery. When the voltage of the first secondary battery is equal to or higher than the voltage of the second secondary battery in the state of being equal to the higher one, the first relay is controlled so that the first relay is turned on, Means for controlling the second relay so that the second relay is turned on when the first relay is turned on and the voltage of the first secondary battery is equal to the voltage of the second secondary battery. It can also be. The boost converter includes a first switching element connected to the first positive electrode bus, a second switching element connected to the first switching element and the negative electrode bus, the first switching element, and the first switching element. An intermediate point between the two switching elements and the reactor connected to the second positive electrode bus, and when the switching control unit switches from the series connection state to the parallel connection state, the third relay After being turned off, the boost converter is controlled so that the device voltage is equal to the higher one of the voltage of the first secondary battery and the voltage of the second secondary battery, and the device voltage is the first voltage. When the voltage of the first secondary battery is less than the voltage of the second secondary battery in a state in which the voltage of the secondary battery and the voltage of the second secondary battery are equal to the higher one, the second relay The second relay is controlled to be turned on, and the step-up converter is controlled so that the first switching element is held on with the second relay being turned on. It may be a means for controlling the first relay so that the first relay is turned on in a state where the voltage and the voltage of the second secondary battery are equal.

  In the power supply device of the present invention, the second secondary battery is a battery having a higher rated voltage than the first secondary battery, the first relay is on, the second relay, the third relay, A first connection state in which only the first secondary battery of the first secondary battery and the second secondary battery is connected to the device when the fourth relay is off; Only the second secondary battery out of the first secondary battery and the second secondary battery is caused by the relay being on and the first relay, the third relay, and the fourth relay being off. The second secondary battery is connected to the device, and the first secondary battery is turned on when the third relay is on and the first relay, the second relay, and the fourth relay are off. The second secondary battery is connected in series as viewed from the device. When switching the third connection state, the boost converter, the first relay, the second relay, and the third relay are switched so that the device voltage is adjusted while the fourth relay is turned on. And a switching control means for controlling the fourth relay.

  The vehicle of the present invention is a power supply device of the present invention according to any one of the above-described aspects, that is, a power supply device that basically exchanges power with a device that operates by electric power, and the negative electrode side terminal of the device is A first secondary battery in which a negative electrode side terminal is connected to the connected negative electrode bus; a second secondary battery in which a positive electrode side terminal is connected to a first positive electrode bus to which the positive electrode side terminal of the device is connected; A first relay for connecting and releasing a positive electrode side terminal of the first secondary battery and a positive electrode side terminal of the second secondary battery; a negative electrode side terminal of the first secondary battery; and the second secondary battery. A second relay for connecting to and disconnecting from the negative electrode side terminal of the battery, and a second relay for connecting to and disconnecting from the positive electrode side terminal of the first secondary battery and the negative electrode side terminal of the second secondary battery. 3 relay and a second positive electrode bus to which the positive terminal of the first secondary battery is connected A booster that is connected to the first positive electrode bus and the negative electrode bus, and that is a voltage between the first positive electrode bus and the negative electrode bus, is an equipment voltage that is a voltage between the first positive electrode bus and the negative electrode bus. A step-up converter that can be adjusted at a pre-voltage or higher, and a fourth relay that is provided on the second positive electrode bus and connects and disconnects the positive side terminal of the first secondary battery and the step-up converter. The gist is to mount a power supply device and to mount the device as a device that outputs driving power.

  Since the vehicle of the present invention is equipped with the power supply device of the present invention according to any one of the above-described aspects, the effects of the power supply device of the present invention, for example, the first secondary battery and the second secondary battery as viewed from the device. The effect which makes it possible to suppress that an apparatus voltage changes suddenly when switching a connection state with can be show | played.

It is a block diagram which shows the outline of a structure of the electric vehicle 20 carrying the power supply device as 1st Example of this invention. It is explanatory drawing which shows an example of the map for a target connection state setting. 4 is a flowchart showing an example of a parallel / serial switching control routine executed by an electronic control unit 50. 4 is a flowchart showing an example of a serial / parallel switching control routine executed by an electronic control unit 50. Times of ON / OFF states of relays Rp1, Rp2, Rs, Rc, charge / discharge currents Ib1, Ib2 of the batteries 40, 42, current Ic of the second positive bus 37, and device voltage Vh when switching from the parallel connection state to the series connection state It is explanatory drawing which shows the mode of a change typically. Times of ON / OFF states of relays Rp1, Rp2, Rs, Rc, charge / discharge currents Ib1, Ib2 of the batteries 40, 42, current Ic of the second positive bus 37, and device voltage Vh when switching from the serial connection state to the parallel connection state It is explanatory drawing which shows the mode of a change typically. It is explanatory drawing which shows an example of the target connection state setting map of 2nd Example.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of an electric vehicle 20 equipped with a power supply device as a first embodiment of the present invention. As shown in the figure, the electric vehicle 20 of the first embodiment is configured as a synchronous generator motor, for example, and a motor 30 having a rotor connected to a drive shaft 26 that is connected to drive wheels 22a and 22b via a differential gear 24. An inverter 32 for driving the motor 30, a battery 40 having a negative terminal connected to a negative bus 35 connected to a negative terminal of the inverter 32, and a first terminal having a positive terminal connected to the inverter 32. A battery 42 having a positive terminal connected to the positive bus 36, a relay Rp 1 that connects and disconnects the positive terminal of the battery 40, the positive terminal of the battery 42, and the first positive bus 36; Relay Rp2 that connects and disconnects the negative electrode side terminal or negative electrode bus 35 and the negative electrode side terminal of the battery 42, and the positive electrode side of the battery 40 Relay Rs that connects and disconnects the battery and the negative terminal of battery 42, and is connected to negative bus 35, first positive bus 36, and second positive bus 37 to which the positive terminal of battery 40 is connected. The boost converter 34, the relay Rc provided on the second positive bus 37 for connecting and disconnecting the battery 40 and the boost converter 34, the electronic control unit 50 for controlling the entire vehicle, and the second positive bus 37. And a capacitor 38 attached to the negative electrode bus 35, and a capacitor 39 attached to the first positive electrode bus 36 and the negative electrode bus 35.

  The batteries 40 and 42 are configured as secondary batteries such as lithium ion secondary batteries, for example. In the first embodiment, the batteries having the same rated voltage (for example, several hundred volts) are used.

  Boost converter 34 includes two transistors T1 and T2, two diodes D1 and D2 connected in parallel to transistors T1 and T2, and a reactor L. The two transistors T1 and T2 are connected to the first positive electrode bus 36 and the negative electrode bus 35, respectively, and the reactor L is connected to the intermediate point of the transistors T1 and T2 and the second positive electrode bus 37. In this step-up converter 34, the transistors T1 and T2 are turned on / off to control the voltage Vh between the first positive bus 36 and the negative bus 35 (the voltage of the capacitor 39, hereinafter referred to as device voltage) Vh to the second positive bus 37. And the negative electrode bus 35 (voltage of the capacitor 38, hereinafter referred to as pre-boosting voltage) Vl or higher.

  The electronic control unit 50 is configured as a microprocessor centered on the CPU 52. In addition to the CPU 52, a ROM 54 that stores processing programs, a RAM 56 that temporarily stores data, input / output ports and communication ports (not shown), and the like. Is provided. The electronic control unit 50 includes a rotational position of the motor 30 from a rotational position detection sensor (not shown) that detects the rotational position of the rotor of the motor 30 and a current sensor (not shown) that detects a phase current that is supplied to the motor 30. The phase current of the motor 30, the pre-boosting voltage Vl from the voltage sensor 38 a attached between the terminals of the capacitor 38, the device voltage Vh from the voltage sensor 39 a attached between the terminals of the capacitor 39, and the terminal of the battery 40. The voltage sensor 43a attached between the terminals of the battery 40 and the charge / discharge current Ib1 of the battery 40 from the current sensor 41b attached to the positive terminal of the battery 40. Is attached to the positive terminal of the battery 42. Among the charge / discharge current Ib2 of the battery 42 from the current sensor 43b2 and the first positive electrode bus 36, the connection point with the transistor T1 of the step-up converter 34 (hereinafter referred to as the battery side range of the first positive electrode bus 36). The current Ip in the battery side range of the first positive electrode bus 36 from the current sensor 46 attached to the current sensor 46, the current Ic of the second positive electrode bus 37 from the current sensor 48 attached to the second positive electrode bus 37, and from the ignition switch 60 Ignition signal, shift position SP from the shift position sensor 62 that detects the operation position of the shift lever, accelerator opening Acc from the accelerator pedal position sensor 64 that detects the depression amount of the accelerator pedal, and brake that detects the depression amount of the brake pedal The pedal position from the pedal position sensor 66 Rk in pedal position BP, and a vehicle speed V from a vehicle speed sensor 68 is input through the input port. Further, the electronic control unit 50 provides a switching control signal to a switching element (not shown) of the inverter 32, a switching control signal to the transistors T1 and T2 of the boost converter 34, an on / off signal to the relays Rp1, Rp2, Rs, and Rc. Is output through the output port.

  Here, the hardware configuration of the power supply device of the first embodiment mainly includes the batteries 40 and 42, the boost converter 34, the relays Rp1, Rp2, Rs, Rc, and the electronic control unit 50.

  In the power supply device mounted on the electric vehicle 20 of the first embodiment thus configured, when the relays Rp1 and Rp2 are on and the relays Rs and Rc are off, the battery 40 and the battery 42 are connected to the inverter 32 side. When the relay Rs is on and the relays Rp1, Rp2, and Rc are off, the battery 40 and the battery 42 are viewed from the inverter 32 side. Are connected in series (hereinafter, this state is referred to as a series connection state).

  Further, the electric vehicle 20 of the first embodiment basically travels by drive control described below that is executed by the electronic control unit 50. The electronic control unit 50 first sets a required torque Td * required for the drive shaft 26 for traveling on the basis of the accelerator opening Acc from the accelerator pedal position sensor 64 and the vehicle speed V from the vehicle speed sensor 68. Based on the set required torque Td * and the vehicle speed V, a target connection state is set as a target of the connection state of the batteries 40 and 42 viewed from the inverter 32 side. Here, in the first embodiment, the target connection state is determined in advance by storing the relationship between the required torque Td *, the vehicle speed V, and the target connection state in the ROM 54 as a target connection state setting map, and the required torque Td *. When the vehicle speed V is given, the corresponding target connection state is derived from the stored map and set. An example of the target connection state setting map is shown in FIG. When the current connection state of the batteries 40 and 42 viewed from the inverter 32 side and the target connection state are the same, the required torque Td * is applied to the drive shaft 26 while maintaining the current connection state. The switching control of the switching element of the inverter 32 is performed so that the output is output. When the current connection state and the target connection state are different, the required torque Td * is output to the drive shaft 26 while switching from the current connection state to the target connection state. The switching control of the switching element of the inverter 32 is performed. By performing such control, when the connection state of the batteries 40 and 42 viewed from the inverter 32 side is not switched (when the relays Rp1, Rp2, Rs, and Rc are kept on / off), the batteries 40 and 42 and the inverter are connected. 32, power is exchanged via the negative electrode bus 35 and the first positive electrode bus 36 without going through the boost converter 34. Therefore, loss due to the boost converter 34 can be suppressed, and power exchange can be performed. It can be performed efficiently.

  Next, the operation of the power supply device mounted on the electric vehicle 20 of the first embodiment configured as described above, particularly the operation when switching between the parallel connection state and the series connection state will be described. FIG. 3 is a flowchart showing an example of a parallel / serial switching control routine executed by the electronic control unit 50, and FIG. 4 is a flowchart showing an example of a serial / parallel switching control routine executed by the electronic control unit 50. . 3 is executed when the current connection state is the parallel connection state and the target connection state is the serial connection state, and the serial / parallel switching control routine of FIG. 4 is executed when the current connection state is the serial connection state. And is executed when the target connection state is a parallel connection state. Hereinafter, the parallel / serial switching control routine of FIG. 3 will be described first, and then the serial / parallel switching control routine of FIG. 4 will be described.

  When the parallel / serial switching control routine of FIG. 3 is executed, the CPU 52 of the electronic control unit 50 first turns on the relay Rc (step S100). Through this process, the positive terminal of the battery 40 is connected to the positive terminal of the battery 42 and the first positive bus 36 via the power line (see FIG. 1) provided with the relay Rp1, It is also connected to reactor L of boost converter 34 via second positive electrode bus 37.

  Subsequently, the current Ip in the battery side range of the first positive electrode bus 36 from the current sensor 46 is input (step S110), and whether or not the input current Ip in the battery side range of the first positive electrode bus 36 is 0. (Step S120), and when it is determined that the current Ip in the battery-side range of the first positive bus 36 is not 0, the voltage is increased so that the current Ip in the battery-side range of the first positive bus 36 becomes 0. When switching control is performed on the transistors T1 and T2 of the converter 34 (step S130), the process returns to step S110, and when it is determined in step S120 that the current Ip in the battery side range of the first positive electrode bus 36 is 0, the relay Rp1 and Rp2 are turned off (step S140). Here, the process of step S130 is a process of setting the current Ip in the battery side range of the first positive electrode bus 36 to the value 0 by slightly increasing the device voltage Vh. Further, by the process of step S140, the positive terminal of the battery 40 is disconnected from the positive terminal of the battery 42 and the first positive bus 36, and the negative terminal of the battery 42 is disconnected from the negative terminal of the battery 40 and the negative bus 35. It is. At this time, the connection between the positive terminal of battery 40 and reactor L of boost converter 34 is continued.

  Subsequently, the device voltage Vh from the voltage sensor 39a, the terminal voltage Vb2 of the battery 40 from the voltage sensor 41a, and the terminal voltage Vb2 of the battery 42 from the current sensor 43b are input (step S150), and the input device voltage is input. Vh is compared with the sum of the inter-terminal voltage Vb1 of the battery 40 and the inter-terminal voltage Vb2 of the battery 42 (step S160), and the device voltage Vh is the sum of the inter-terminal voltage Vb1 of the battery 40 and the inter-terminal voltage Vb2 of the battery 42. If it is less than the threshold voltage, switching control is performed on the transistors T1 and T2 of the boost converter 34 so that the device voltage Vh is equal to or higher than the sum of the inter-terminal voltage Vb1 of the battery 40 and the inter-terminal voltage Vb2 of the battery 42 (step S170). In step S160, the device voltage Vh is changed between the terminals of the battery 40. When more than the sum of the Vb1 and the terminal voltage Vb2 of the battery 42, and turns on the relay Rs (step S180). In this way, the device voltage Vh can be adjusted by turning on the relay Rs in a state where the device voltage Vh is equal to or higher than the sum of the voltage Vb1 between the terminals of the battery 40 and the voltage Vb2 between the terminals of the battery 42, and making a series connection. Therefore, the device voltage Vh can be prevented from changing suddenly when the relay Rs is turned on as compared with the case where the relay Rs is turned on.

  Then, the charging / discharging current Ib2 of the battery 42 from the current sensor 43b and the current Ic of the second positive bus 37 from the current sensor 48 are input (step S190), and the charging / discharging current Ib2 of the battery 42 is input to the battery 42. Is compared with a predetermined threshold value Iref1 for confirming charging / discharging of the battery 42, and it is determined whether or not the current Ic of the second positive electrode bus 37 is 0 (step S200). The charging / discharging current Ib2 of the battery 42 is determined as a threshold value. When it is less than Iref1 or when current Ic of second positive bus 37 is not 0, boost converter 34 is such that charge / discharge current Ib2 of battery 42 is equal to or greater than threshold Iref1 and current Ic of second positive bus 37 is 0. The transistors T1 and T2 are controlled to switch (step S210), and the process returns to step S190. When the current Ic of the second positive bus 37 with charging and discharging current Ib2 of the battery 42 is the threshold value Iref1 or value 0 in 200, (step S220) The relay Rc as an off to end the routine.

  FIG. 5 shows ON / OFF states of relays Rp1, Rp2, Rs, Rc when switching from the parallel connection state to the series connection state, the charge / discharge currents Ib1, Ib2 of the batteries 40, 42, the current Ic of the second positive electrode bus 37, and the device voltage. It is explanatory drawing which shows typically the mode of a time change with Vh. When performing this switching, as shown in the figure, first, relay Rc is turned on (time t1), device voltage Vh is slightly increased by control of boost converter 34, and charge / discharge current Ib2 (first 1 Relays Rp1 and Rp2 are turned off (time t2) in a state in which the current Ip in the battery side range of the positive electrode bus 36 becomes zero. Under the control of the boost converter 34, the device voltage Vh is increased to the sum of the voltage Vb1 between the terminals of the battery 40 and the voltage Vb2 between the terminals of the battery 42, and the relay Rs is turned on in this state (time t3). 34, the device voltage Vh is adjusted to the sum of the inter-terminal voltage Vb 1 of the battery 40 and the inter-terminal voltage Vb 2 of the battery 42, and the charge / discharge current Ib 2 of the battery 42 increases and the current Ic of the second positive bus 37 is increased. The relay Rc is turned off when the value becomes 0 (time t4). By such control, it is possible to suppress the device voltage Vh from changing suddenly when the relay Rs is turned on, as compared with the case where the relay Rs is turned on without adjusting the device voltage Vh.

  Next, the serial / parallel switching control routine of FIG. 4 will be described. When this routine is executed, the CPU 52 of the electronic control unit 50 first turns on the relay Rc (step S300). With this process, the positive terminal of the battery 40 is connected to the negative terminal of the battery 42 via the power line (see FIG. 1) provided with the relay Rs, and in addition, the second positive bus 37 is connected. To the reactor L of the step-up converter 34.

  Subsequently, the charging / discharging current Ib2 of the battery 42 from the current sensor 43b and the current Ic of the second positive bus 37 from the current sensor 48 are input (step S310), and the input current Ic of the second positive bus 37 is input. It is compared with a threshold value Iref2 (for example, the same value as the threshold value Iref1) determined to confirm the energization of the second positive electrode bus 37, and it is determined whether or not the charge / discharge current Ib2 of the battery 42 is a value of 0. (Step S320) When the current Ic of the second positive bus 37 is less than the threshold value Iref2 or when the charge / discharge current Ib2 of the battery 42 is not 0, the current Ic of the second positive bus 37 becomes equal to or greater than the threshold Iref2 and the battery 42. Switching control is performed on the transistors T1 and T2 of the step-up converter 34 so that the charge / discharge current Ib2 becomes zero (step S 30) Returning to step S310, when the current Ic of the second positive electrode bus 37 is not less than the threshold value Iref2 and the charge / discharge current Ib2 of the battery 42 is 0 in step S320, the relay Rs is turned off (step S340). . Here, the process of step S330 is a process of setting the current Ic of the second positive bus 37 to the threshold value Iref2 or more and setting the charge / discharge current Ib2 of the battery 42 to the value 0 by slightly increasing the device voltage Vh. Further, the positive terminal of the battery 40 and the negative terminal of the battery 42 are disconnected by the process of step S340. At this time, the connection between the positive terminal of battery 40 and reactor L of boost converter 34 is continued.

  Then, the device voltage Vh from the voltage sensor 39a and the inter-terminal voltages Vb1, Vb2 of the batteries 40, 42 from the voltage sensors 41a, 43b are input (step S350), and the input device voltage Vh is used as the inter-terminal voltage of the battery 40. When the device voltage Vh is higher than the higher one of the inter-terminal voltage Vb1 of the battery 40 and the inter-terminal voltage Vb2 of the battery 42 when compared with the higher one of Vb1 and the inter-terminal voltage Vb2 of the battery 42 (step S360). The transistors T1 and T2 of the boost converter 34 are controlled to be switched so that the device voltage Vh is equal to the higher one of the inter-terminal voltage Vb1 of the battery 40 and the inter-terminal voltage Vb2 of the battery 42 (step S370), and the process proceeds to step S350. In step S360, the device voltage Vh is the voltage across the terminals of the battery 40. When equal to higher of the b1 and the terminal voltage Vb2 of the battery 42, it compares the terminal voltage Vb2 of terminal voltage Vb1 and battery 42 of the battery 40 at that time (step S380).

  When the inter-terminal voltage Vb1 of the battery 40 is equal to or higher than the inter-terminal voltage Vb2 of the battery 42, the relay Rp1 is turned on (step S390). In this way, when the relay Rp1 is turned on by turning on the relay Rp1 and connecting the positive terminal of the battery 40 to the first positive bus 36 in a state where the device voltage Vh is equal to the inter-terminal voltage Vb1 of the battery 40. It is possible to suppress a sudden change in the device voltage Vh.

  Then, the inter-terminal voltage Vb1 of the battery 40 from the voltage sensor 41a and the inter-terminal voltage Vb2 of the battery 42 from the voltage sensor 43a are input (step S400), and the input inter-terminal voltage Vb1 of the battery 40 and the battery 42 The inter-terminal voltage Vb2 is compared (step S410). If the inter-terminal voltage Vb1 of the battery 40 and the inter-terminal voltage Vb2 of the battery 42 are not equal, the process returns to step S400, and in step S410, the inter-terminal voltage Vb1 When the inter-terminal voltage Vb2 of the battery 42 is equal, the relay Rp2 is turned on (step S420), the current Ic of the second positive bus 37 from the current sensor 48 is input (step S480), and the input second positive electrode It is determined whether or not the current Ic of the bus bar 37 is 0 (step S4). 0), when the current Ic of the second positive bus 37 is not 0, the process returns to step S480. When the current Ic of the second positive bus 37 is 0, the relay Rc is turned off (step S500), and this routine is terminated. To do. In other words, in a state where the positive terminal of the battery 40 is connected to the first positive bus 36, power is supplied from the battery 40 to the inverter 32 so that the voltage Vb1 between the terminals of the battery 40 and the voltage Vb2 between the terminals of the battery 42 are equal. In this state, the relay Rp2 is turned on to establish a parallel connection state. Thereby, it is possible to suppress the device voltage Vh from changing suddenly when the relay Rp2 is turned on. At this time, the boost converter 34 is stopped.

  When the terminal voltage Vb1 of the battery 40 is less than the terminal voltage Vb2 of the battery 42 in step S380, the relay Rp2 is turned on (step S430). As described above, when the relay Rp2 is turned on by turning on the relay Rp2 and connecting the negative terminal of the battery 42 to the negative bus 35 in a state where the equipment voltage Vh is equal to the inter-terminal voltage Vb2 of the battery 42, A sudden change in Vh can be suppressed.

  Then, the transistor T1 of the boost converter 34 is controlled so that the transistor T1 of the boost converter 34 is on and the transistor T2 is off (step S440), and the voltage Vb1 between the terminals of the battery 40 from the voltage sensor 41a and the voltage sensor are controlled. The terminal voltage Vb2 of the battery 42 from 43a is input (step S450), and the terminal voltage Vb1 of the battery 40 and the terminal voltage Vb2 of the battery 42 are compared (step S460). When the voltage Vb1 between the terminals of the battery 42 and the voltage Vb2 between the terminals of the battery 42 are not equal, the process returns to step S450, and when the voltage Vb1 between the terminals of the battery 40 and the voltage Vb2 between the terminals of the battery 42 are equal in step S460 (Step S470) The current Ic of the second positive electrode bus 37 from the power supply 48 is input (step S480), and it is determined whether or not the input current Ic of the second positive electrode bus 37 is 0 (step S490). When the current Ic of the bus 37 is not 0, the process returns to step S480. When the current Ic of the second positive bus 37 is 0, the relay Rc is turned off (step S500), and this routine is terminated. Thus, in a state where the negative electrode side terminal of the battery 42 is connected to the negative electrode bus 35, electric power is supplied from the battery 42 to the inverter 32, or electric power is supplied to the battery 40 via the transistor T 1 and the reactor L of the boost converter 34. In other words, the relay Rp1 is turned on in a state where the voltage Vb1 between the terminals of the battery 40 and the voltage Vb2 between the terminals of the battery 42 are equal to each other, thereby establishing a series connection state. Thereby, when relay Rp1 is turned ON, it can suppress that the apparatus voltage Vh changes suddenly. Moreover, since the power is supplied from the battery 42 not only to the inverter 32 but also to the battery 40 through the transistor T1 and the reactor L by turning on the transistor T1 of the boost converter 34, the inter-terminal voltage Vb1 of the battery 40 is also supplied. And the terminal voltage Vb2 of the battery 42 can be equalized more quickly.

  FIG. 6 shows ON / OFF states of relays Rp1, Rp2, Rs, Rc when switching from the series connection state to the parallel connection state, the charge / discharge currents Ib1, Ib2 of the batteries 40, 42, the current Ic of the second positive electrode bus 37, and the device voltage. It is explanatory drawing which shows typically the mode of a time change with Vh. When this switching is performed, first, as shown in the figure, the relay Rc is turned on (time t5), the device voltage Vh is slightly increased by the control of the boost converter 34, and the current Ic of the second positive bus 37 increases. At the same time, the relay Rs is turned off in a state where the charge / discharge current Ib2 of the battery 42 becomes 0 (time t6). Then, by controlling the boost converter 34, the device voltage Vh is lowered to a higher one of the inter-terminal voltage Vb1 of the battery 40 and the inter-terminal voltage Vb2 of the battery 42 (in the example of FIG. 6, both are the same). In this state, relays Rp1 and Rp2 are turned on (time t7), and then relay Rc is turned off (time t8) in a state where current Ic of second positive bus 37 has a value of 0. By such control, it is possible to suppress the device voltage Vh from changing suddenly when the relays Rp1, Rp2 are turned on, as compared with the case where the relays Rp1, Rp2 are turned on without adjusting the device voltage Vh.

  According to the power supply device mounted on the electric vehicle 20 of the first embodiment described above, the battery 40 having the negative electrode side terminal connected to the negative electrode bus 35 and the battery having the positive electrode side terminal connected to the first positive electrode bus 36. 42, relay Rp1 interposed between the positive terminal of battery 40 and the positive terminal of battery 42, relay Rp2 interposed between the negative terminal of battery 40 and the negative terminal of battery 42, and the positive side of battery 40 Relay Rs interposed between the terminal and the negative terminal of battery 42, boost converter 34 connected to negative bus 35, first positive bus 36, and second positive bus 37 to which the positive terminal of battery 40 is connected; A relay Rc provided on the second positive electrode bus 37, and the boost converter 34 does not adjust the device voltage Vh in the switching process between the parallel connection state and the series connection state. Since performing et al., It is possible to prevent the equipment voltage Vh is suddenly changed at this time. As a result, inconveniences such as an inrush current flowing between the batteries 40 and 42 and the inverter 32 or a decrease in controllability of the inverter 32 can be suppressed.

  In the power supply device mounted on the electric vehicle 20 of the first embodiment, when switching from the parallel connection state to the series connection state, the charging / discharging current Ib2 of the battery 42 becomes equal to or higher than the threshold value Iref1 after the relay Rs is turned on. Boost converter 34 is controlled so that current Ic of second positive bus 37 has a value of 0, while charge / discharge current Ib2 of battery 42 is equal to or greater than threshold value Iref1 and current Ic of second positive bus 37 is 0. Although the relay Rc is turned off, the boost converter 34 is controlled or the relay Rc is turned off by paying attention only to the current Ic of the second positive bus 37 regardless of the charging / discharging current Ib2 of the battery 42. Also good.

  In the power supply device mounted on the electric vehicle 20 of the first embodiment, when switching from the series connection state to the parallel connection state, the current Ic of the second positive electrode bus 37 becomes equal to or greater than the threshold value Iref2 after the relay Rc is turned on. At the same time, the boost converter 34 is controlled so that the charge / discharge current Ib2 of the battery 42 becomes 0, and the current Ic of the second positive bus 37 is not less than the threshold value Iref2 and the charge / discharge current Ib2 of the battery 42 is 0. Although the relay Rs is turned off, the boost converter 34 is controlled or the relay Rs is turned off by paying attention only to the charging / discharging current Ib2 of the battery 42 regardless of the current Ic of the second positive bus 37. Also good.

  In the power supply device mounted on the electric vehicle 20 of the first embodiment, when switching from the serial connection state to the parallel connection state, the device voltage Vh is the voltage between the terminals Vb1 of the battery 40 and the voltage Vb2 between the terminals of the battery 42. When the voltage Vb1 between the terminals of the battery 40 is less than the voltage Vb2 between the terminals of the battery 42 when equal to the higher one, the relay Rp2 is turned on and the transistor T1 of the boost converter 34 is turned on to turn the battery 42 into the inverter 32. When power is supplied or power is supplied to the battery 40 via the transistor T1 and the reactor L of the boost converter 34, the voltage Vb1 between the terminals of the battery 40 and the voltage Vb2 between the terminals of the battery 42 become equal. Rp2 is turned on, but transistor T1 is not turned on That is, when the boost converter 34 is stopped and the power is supplied from the battery 42 to the inverter 32 and the voltage Vb1 between the terminals of the battery 40 and the voltage Vb2 between the terminals of the battery 42 become equal, the relay Rp2 is turned on. It is good.

  In the power supply device mounted on the electric vehicle 20 of the first embodiment, the device voltage Vh is adjusted by the boost converter 34 both when switching from the parallel connection state to the series connection state and when switching from the series connection state to the parallel connection state. However, it may be performed while adjusting the device voltage Vh only in either case.

  Next, an electric vehicle 20B as a second embodiment of the present invention will be described. The electric vehicle 20B of the second embodiment has the same hardware configuration as the electric vehicle 20 of the first embodiment described with reference to FIG. 1 except that the rated voltage of the battery 40 and the rated voltage of the battery 42 are different. is doing. Therefore, in order to avoid redundant description, detailed description of the hardware configuration of the electric vehicle 20B of the second embodiment is omitted. In the second embodiment, the rated voltages of the batteries 40 and 42 are the first voltage (for example, 200V) and the second voltage (for example, 400V) higher than the first voltage, respectively.

  In the power supply device mounted on the electric vehicle 20B of the second embodiment, the rated voltages of the batteries 40 and 42 are different, so that the connection state of the batteries 40 and 42 viewed from the inverter 32 cannot be a parallel connection state. Therefore, in the second embodiment, when the relay Rp1 is on and the relays Rp2, Rs, Rc are off, only the battery 40 of the batteries 40, 42 is connected to the inverter 32, and the relay When Rp2 is on and relays Rp1, Rs, Rc are off, only the battery 42 of the batteries 40, 42 is connected to the inverter 32, and the above-described series connection state is required torque. Switching is made based on Td * and vehicle speed V. Specifically, as in the first embodiment, the target connection state is set using the target connection state setting map of FIG. 7 based on the required torque Td * and the vehicle speed V, and the current connection state and the target connection state are set. Is different from the current connection state to the target connection state.

  Even in the power supply device mounted on the electric vehicle 20B of the second embodiment configured as described above, when switching between the first connection state, the second connection state, and the series connection state, the same as the electric vehicle 20 of the first embodiment. In addition, switching is performed while adjusting the device voltage Vh by the boost converter 34 with the relay Rc turned on. Hereinafter, the case of switching between the first connection state and the second connection state and the case of switching between the second connection state and the series connection state will be described.

  When switching from the first connection state to the second connection state, the relay Rc is turned on so that the current Ip in the battery side range of the first positive electrode bus 36 becomes 0 by the control of the boost converter 34, and the first positive electrode The relay Rp1 is turned off in a state where the current Ip in the battery side range of the bus 36 becomes zero. The device voltage Vh is raised to the inter-terminal voltage Vb2 of the battery 42 by the control of the boost converter 34, and in this state, the relay Rp2 is turned on to enter the second connection state. Thereby, it is possible to suppress the device voltage Vh from changing suddenly when the relay Rp2 is turned on. Thereafter, the boost converter 34 is stopped driving, and the relay Rc is turned off in a state where the current Ic of the second positive electrode bus 37 is zero.

  When switching from the second connection state to the first connection state, the relay Rc is turned on, and the current Ip (charge / discharge current Ib2 of the battery 42) in the battery side range of the first positive bus 36 is controlled by the control of the boost converter 34. In this state, the relay Rp2 is turned off. Then, the device voltage Vh is reduced to the inter-terminal voltage Vb1 of the battery 40 by the control of the boost converter 34, and in this state, the relay Rp1 is turned on to enter the first connection state. Thereby, when relay Rp1 is turned ON, it can suppress that the apparatus voltage Vh changes suddenly. Thereafter, the boost converter 34 is stopped driving, and the relay Rc is turned off in a state where the current Ic of the second positive electrode bus 37 is zero.

  When switching from the second connection state to the series connection state, the relay Rc is turned on so that the current Ip in the battery side range of the first positive electrode bus 36 becomes 0 by the control of the boost converter 34, and the first positive electrode bus The relay Rp2 is turned off in a state where the current Ip in the battery-side range of 36 is zero. Then, the device voltage Vh is raised to the sum of the inter-terminal voltage Vb1 of the battery 40 and the inter-terminal voltage Vb2 of the battery 42 by the control of the boost converter 34, and in this state, the relay Rs is turned on to establish a serial connection state. Thereby, it is possible to suppress the device voltage Vh from changing suddenly when the relay Rs is turned on. Thereafter, the boost converter 34 is stopped driving, and the relay Rc is turned off in a state where the current Ic of the second positive electrode bus 37 is zero.

  When switching from the serial connection state to the second connection state, the relay Rc is turned on, and the current Ip in the battery side range of the first positive bus 36 (the charge / discharge current Ib2 of the battery 42) is 0 by the control of the boost converter 34. In this state, the relay Rs is turned off. Then, the device voltage Vh is lowered to the inter-terminal voltage Vb2 of the battery 42 by the control of the boost converter 34, and in this state, the relay Rp2 is turned on to enter the second connection state. Thereby, it is possible to suppress the device voltage Vh from changing suddenly when the relay Rp2 is turned on. Thereafter, the boost converter 34 is stopped driving, and the relay Rc is turned off in a state where the current Ic of the second positive electrode bus 37 is zero.

  According to the power supply device mounted on the electric vehicle 20B of the second embodiment described above, the device voltage Vh is generated by the boost converter 34 with the same hardware configuration as that of the power supply device mounted on the electric vehicle 20 of the first embodiment. Since the first connection state, the second connection state, and the series connection state are switched while adjusting, the device voltage Vh can be prevented from suddenly changing at this time. As a result, inconveniences such as an inrush current flowing between the batteries 40 and 42 and the inverter 32 or a decrease in controllability of the inverter 32 can be suppressed.

  In the power supply device mounted on the electric vehicle 20B according to the second embodiment, both when switching from the first connection state to the second connection state and when switching from the second connection state to the first connection state, the second connection state is connected in series. When switching to the connection state or switching from the series connection state to the second connection state, it is performed while adjusting the device voltage Vh by the boost converter 34, but it is performed while adjusting the device voltage Vh only at least one time. It may be a thing.

  In the electric vehicles 20 and 20B of the first and second embodiments, the auxiliary machine is not described, but the auxiliary machine may be connected to the negative electrode bus 35 and the second positive electrode bus 37. If it carries out like this, it can be operated using the electric power from the battery 40.

  In the first embodiment and the second embodiment, the power supply device mounted on the simple electric vehicles 20 and 20B that travel using only the power from the motor 30 without the engine is described. It is good also as a power supply device mounted in the hybrid vehicle which drive | works using the motive power from a motor.

  Further, the power supply device is not limited to such a power supply device mounted on an automobile, and any power supply device mounted on a moving body such as a vehicle, a ship, or an aircraft as long as it is a power supply device that exchanges power with a device that operates with electric power. It may be a device or a power supply device incorporated in a construction facility or the like.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the battery 40 corresponds to the “first secondary battery”, the battery 42 corresponds to the “second secondary battery”, the relay Rp1 corresponds to the “first relay”, and the relay Rp2 corresponds to the “second secondary battery”. The relay Rs corresponds to the “third relay”, the boost converter 34 corresponds to the “boost converter”, and the relay Rc corresponds to the “fourth relay”. Further, the electronic control unit 50 that executes the parallel / serial switching control routine of FIG. 3 or the serial / parallel switching control routine of FIG. 4 that performs switching processing between the parallel connection state and the serial connection state while adjusting the device voltage Vh by the boost converter 34. Corresponds to “switching control means”. Further, the electronic control unit 50 that performs switching processing between the first connection state and the second connection state and switching processing between the second connection state and the series connection state while adjusting the device voltage Vh by the boost converter 34 is also referred to as “switching control means”. Is equivalent to.

  Here, the “first secondary battery” is not limited to the battery 40 configured as a lithium ion secondary battery, but is a device such as a nickel hydride secondary battery, a nickel cadmium secondary battery, or a lead storage battery. Any type of secondary battery may be used as long as the negative electrode side terminal is connected to the negative electrode bus to which the negative electrode side terminal is connected. The “secondary secondary battery” is not limited to the battery 42 configured as a lithium ion secondary battery, but is a positive terminal of a device such as a nickel hydride secondary battery, a nickel cadmium secondary battery, or a lead storage battery. Any type of secondary battery may be used as long as the positive electrode terminal is connected to the first positive electrode bus to which is connected. The “first relay” is not limited to the relay Rp1 as long as it connects and disconnects the positive terminal of the first secondary battery and the positive terminal of the second secondary battery. It doesn't matter what. The “second relay” is not limited to the relay Rp2 as long as it connects and disconnects the negative terminal of the first secondary battery and the negative terminal of the second secondary battery. It doesn't matter what. The “third relay” is not limited to the relay Rs as long as it connects and disconnects the positive terminal of the first secondary battery and the negative terminal of the second secondary battery. It doesn't matter what. The “boost converter” is not limited to the boost converter 34, and is connected to the second positive bus, the first positive bus, and the negative bus connected to the positive terminal of the first secondary battery. Any device voltage can be used as long as the device voltage, which is the voltage between the positive electrode bus and the negative electrode bus, can be adjusted to be equal to or higher than the pre-boosting voltage, which is the voltage between the second positive electrode bus and the negative electrode bus. The “fourth relay” is not limited to the relay Rc, as long as it is provided on the second positive electrode bus and performs connection and disconnection between the positive terminal of the first secondary battery and the boost converter. It doesn't matter what. The “switching control means” is not limited to one configured by a single electronic control unit 50, and may be configured by a combination of a plurality of electronic control units. Further, the first “switching control means” is not limited to the one that performs the switching process between the parallel connection state and the series connection state while adjusting the device voltage Vh by the boost converter 34. A parallel connection state in which the first secondary battery and the second secondary battery are connected in parallel when viewed from the device by turning on the second relay and turning off the third relay and the fourth relay; A series connection state in which the first secondary battery and the second secondary battery are connected in series when viewed from the device by turning on the third relay and turning off the first relay, the second relay, and the fourth relay. , When the step-up converter, the first relay, the second relay, the third relay, and the fourth relay are controlled so that the device voltage is switched while the device voltage is adjusted while the fourth relay is turned on. How It may be as shall. As the second “switch control means”, the switching process between the first connection state and the second connection state and the switching process between the second connection state and the series connection state are performed while adjusting the device voltage Vh by the boost converter 34. The first relay battery and the second secondary battery are not limited by the first relay being on and the second relay, the third relay, and the fourth relay being off. A first connection state in which only the first secondary battery is connected to the device, and the second relay is on and the first relay, the third relay, and the fourth relay are off, so that the first secondary battery and the second relay are on. A second connection state in which only the second secondary battery among the two secondary batteries is connected to the device, the third relay is on, and the first relay, the second relay, and the fourth relay are off. By the first secondary battery and the second secondary battery The step-up converter, the first relay, the second relay, and the third relay are switched so that the device voltage is adjusted while the fourth relay is turned on when switching the third connection state that is in series connection as viewed from the perspective. As long as it controls the 4th relay and the 4th relay, it does not matter.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the power supply device and vehicle manufacturing industries.

  20, 20B Electric vehicle, 22a, 22b Drive wheel, 24 differential gear, 26 drive shaft, 30 motor, 32 inverter, 34 boost converter, 35 negative bus, 36 first positive bus, 37 second positive bus, 38, 39 capacitor , 38a, 39a Voltage sensor, 40, 42 battery, 41a, 43a Voltage sensor, 41b, 43b, 46, 48 Current sensor, 50 Electronic control unit, 52 CPU, 54 ROM, 56 RAM, 60 Ignition switch, 62 Shift position sensor 64 accelerator pedal position sensor, 66 brake pedal position sensor, 68 vehicle speed sensor, D1, D2 diode, Rp1, Rp2, Rs, Rc relay, T1, T2 transistor.

Claims (8)

A power supply device for exchanging power with a device that operates by electric power,
A first secondary battery in which a negative electrode side terminal is connected to a negative electrode bus to which a negative electrode side terminal of the device is connected;
A second secondary battery having a positive terminal connected to a first positive bus connected to the positive terminal of the device;
A first relay for connecting and releasing the connection between the positive terminal of the first secondary battery and the positive terminal of the second secondary battery;
A second relay that connects and disconnects the negative electrode side terminal of the first secondary battery and the negative electrode side terminal of the second secondary battery;
A third relay for connecting and releasing the connection between the positive terminal of the first secondary battery and the negative terminal of the second secondary battery;
A device connected to the second positive electrode bus connected to the positive terminal of the first secondary battery, the first positive electrode bus and the negative electrode bus, and being a voltage between the first positive electrode bus and the negative electrode bus A step-up converter capable of adjusting a voltage to be equal to or higher than a pre-boosting voltage that is a voltage between the second positive electrode bus and the negative electrode bus;
A fourth relay provided on the second positive electrode bus for connecting and releasing the positive electrode side terminal of the first secondary battery and the boost converter;
A power supply device comprising: The power supply device according to claim 1,
When the first relay and the second relay are on and the third relay and the fourth relay are off, the first secondary battery and the second secondary battery are viewed from the device. The first secondary battery and the second relay when the third relay is turned on and the first relay, the second relay, and the fourth relay are turned off. When switching between a secondary battery and a serial connection state in which the secondary battery is connected in series when viewed from the device, the boost converter and the second switch are switched so that the device voltage is adjusted while the fourth relay is turned on. Switching control means for controlling one relay, the second relay, the third relay, and the fourth relay;
Power supply. The power supply device according to claim 2,
The switching control means controls the fourth relay so that the fourth relay is turned on when switching from the parallel connection state to the series connection state, and the fourth relay is turned on. The boost converter is controlled so that current does not flow in a predetermined range on the second secondary battery side of a connection point with the boost converter in one positive bus, and the current stops flowing in the predetermined range. The first relay and the second relay are controlled so that the first relay and the second relay are turned off, and the device voltage is set while the first relay and the second relay are turned off. The boost converter is controlled to be equal to or higher than the sum of the voltage of the first secondary battery and the voltage of the second secondary battery, and the device voltage is the voltage of the first secondary battery and the second secondary battery. In a state where the sum of The third relay is controlled so that the third relay is turned on, and the second secondary battery is charged and discharged while the third relay is turned on, and current is supplied to the second positive electrode bus. The fourth relay is controlled such that the step-up converter is controlled so as not to flow, the second secondary battery is charged and discharged, and the fourth relay is turned off in a state where no current flows to the second positive electrode bus. Is a means of controlling
Power supply. The power supply device according to claim 2 or 3,
The switching control unit controls the fourth relay so that the fourth relay is turned on when switching from the series connection state to the parallel connection state, and the fourth relay is turned on. The step-up converter is controlled so that a current flows through the second positive electrode bus and the second secondary battery is no longer charged / discharged, and a current flows through the second positive electrode bus and the second secondary battery is charged / discharged. The third relay is controlled so that the third relay is turned off when the third relay is turned off, and the first relay and the second relay are adjusted while the device voltage is adjusted while the third relay is turned off. The step-up converter, the first relay, and the second relay are controlled such that the fourth relay is turned on while the first relay and the second relay are turned on. The fourth re A means for controlling over,
Power supply. The power supply device according to claim 4,
When the switching control means switches from the series connection state to the parallel connection state, after the third relay is turned off, the device voltage becomes the voltage of the first secondary battery and the second secondary battery. The boost converter is controlled to be equal to the higher one of the voltages of the first and second voltages, and the device voltage is equal to the higher one of the voltage of the first secondary battery and the voltage of the second secondary battery. When the voltage of the first secondary battery is equal to or higher than the voltage of the second secondary battery, the first relay is controlled so that the first relay is turned on, the first relay is turned on, and the first relay is turned on. 1 is a means for controlling the second relay so that the second relay is turned on in a state where the voltage of the secondary battery is equal to the voltage of the second secondary battery.
Power supply. The power supply device according to claim 4 or 5, wherein
The boost converter includes a first switching element connected to the first positive bus, a second switching element connected to the first switching element and the negative bus, the first switching element, and the second switching. A reactor connected to an intermediate point of the element and the second positive electrode bus,
When the switching control means switches from the series connection state to the parallel connection state, after the third relay is turned off, the device voltage becomes the voltage of the first secondary battery and the second secondary battery. The boost converter is controlled to be equal to the higher one of the voltages of the first and second voltages, and the device voltage is equal to the higher one of the voltage of the first secondary battery and the voltage of the second secondary battery. When the voltage of the first secondary battery is less than the voltage of the second secondary battery, the second relay is controlled so that the second relay is turned on, and the second relay is turned on. The boost converter is controlled so that the first switching element is kept on, and the first relay is turned on in a state where the voltage of the first secondary battery and the voltage of the second secondary battery are equal. The first relay to be controlled It is a means,
Power supply. The power supply device according to claim 1,
The second secondary battery is a battery having a higher rated voltage than the first secondary battery,
When the first relay is on and the second relay, the third relay, and the fourth relay are off, the first secondary battery and the second secondary battery are out of the first secondary battery. The first second state in which only the secondary battery is connected to the device, and the second relay is on and the first relay, the third relay, and the fourth relay are off. A second connection state in which only the second secondary battery of the secondary battery and the second secondary battery is connected to the device; the third relay is on; and the first relay and the second relay When the fourth relay is switched to the third connection state in which the first secondary battery and the second secondary battery are connected in series as viewed from the device when the fourth relay is off, the fourth relay The device voltage is not adjusted when is turned on. Comprising a switching control means for controlling said boost converter such that the switches al and the first relay and said second relay and the third relay and said fourth relay,
Power supply.   A vehicle on which the power supply device according to any one of claims 1 to 7 is mounted and the device is mounted as a device that outputs power for traveling.